Refining of nonferrous metals



Patented Jan. 22, 1946 REFINING or NONFERROUS METALS Louis S. Deitz,Jr., 'Westiield, N. 3., assignor to Nassau smelting & Refining Company,Incorporated, New York, N. Y., a corporation of New York No Drawing.Application January 9, 1942,

Serial No. 426,168

6 Claims. (CL 204-120) This invention relates to the refining ofnonferrous metals and more particularly to the electrolytic refining ofnon-ferrous metals consisting principally of lead and/or tin andcontainin copper and antimony.

At present there is a considerable quantity of metal on the marketcontaining principally tin, lead, copper and antimony inwhich the copperand antimony together comprise more than 8% of' the metal; There is nomethod now in general use by which the above-mentioned metal can beelectrolytically refined on a commercial basis.

A sulphonic acid electrolyte such as is disclosed .in Patent 2,286,240,granted June 16, 1942, to

J. R. Stack for Refining of non-ferrous metals, will operatesuccessfully to refineanodes made of alloys consisting principally oftin and lead when the anode metal contains relatively small amounts ofcopper and antimony. However, when electrolyzed in asulphonic acidelectrolyte of the type disclosed in that patent, anodes consistingmostly of tin and lead and containing more than 8% of copper andantimony together tend to polarize and may require an excessive voltageto dissolve invention relates particularly to metal such as thatmentioned above, wherein the copper and antimony together comprise morethan about 8% and not more than about 15% of the metal, it is understoodthat similar metal containing less than 8% copper plus antimon inadmixture can be successfully treated in applicant's electrolyte.

One lot ofanodes treated according to theabove-described embodiment ofthe invention analyzed before treatment:

. Per cent Copper 5 Tin 18 Lead 12 Antimony 5 The electrolyte, in thisspecific embodiment of the invention, contains from about 200 to about250 grams per liter of free benzene di-sulphonic acid and from about 3to about 5 grams per liter of hydrochloric acid. Generally, from aboutto about 40 grams per liter oi tin and from about 5 to about 10 gramsper liter of lead in the form of their benzene di-sulphonates are insolution in Objects of this invention are to provide new and improvedelectrolytes for electrolyticallyrefining non-ferrous metals and toprovide new and improved processes for electrolytically refiningnon-ferrous metals.

Further objects and features of the invention will be more apparent fromthe following detailed description.

In general the-invention comprises a process for refining metalconsisting principally of metal of the group consisting of tin, lead,copper and antimony, wherein the copper and antimony taken togethercomprise more than about 8% and not more than about 15% of the metal.This process 1 comprises making anodes oi such metal and electrolyzingthe anodes in an electrolyte consisting benzene di-s'ulphonic acid.Also, the concentration of the sulphonic acid in solution may be zenedi-sulphonate salts.

the electrolyte. The tin and lead may be elec-- trolytically dissolvedin the sulphonic acid electrolyte or may be added in the form of theirben- The temperature of the cell is kept between 50 .to 55 C. and thecurrent density may vary from 8 to 16 amperes per square foot with thevoltage at .35 to .45 volts. Addition agents, such as glue, 4.4 lbs.,and beta naphthol, 2.2 lbs., per ton of cathodes, or any equivalentsthereof, may-be added in order to improve the quality oi the cathodesformed.

After electrolysis the cathodes consisting of 84.2% tin and 15.8% lead,were melted down to form pigs for solder adjustment.

The anode slimes contained:

Per cent Copper 18.2 Tin 54.6 Lead 1.0 Antimony 18.2

These slimes were further'treated to form Babbitt metal.

It is apparent that the invention is susceptible of considerablevariations from the specific embodiment described above. For example,other aromatic sulphonic acids, such as phenol sulphonic acid or itsequivalent, or mixtures of arcmatic sulphonic acids, may be used inplace of varied to suit the type of metal and the electrolyticconditions desired. Thus, either benzene di-sulper liter of hydrochloricacid to prevent polarization of the anodes, whereby tin and lead aredeposited at the cathode.

3. The method of separating metals from metallic materials consistingprincipally of tin and lead and containing at least about 8% but not Amore than about 15% of copper and antimony,

solution to produce chloride ions, can be used in place of hydrochloricacid. If a salt such as sodium chloride is used, steps must be taken toremove the sodium cations to prevent them from building up andinterferring with the platingoperation.

The temperature and current density may likewise be varied to meetchanging conditions. ,The addition agents may be any of those generallyused for the purpose of improving the quality of the cathodes produced.Other changes which are within the spirit of the invention will beapparent to those skilled in the art.

While the benzene di-sulph'onic acid employed may be any one or more ofthe three isomers of this acid, it has been found that successfulresults may be obtained by using a commercially obtainable acid whichconsists principally of metabenzene di-sulphonic acid, but whichcontains variable amounts of the para and ortho forms. The phenolsulphonic acid employed may be the purified product of the directsulphonation of phenol containing a mixture of mono-sulphonated anddi-sulphonated phenol with perhaps small amounts of even highersulphonation products.

What is claimed is:

1. The method of separating metals from metallic materials consistingprincipally of tin and lead and containing at least about 8% but notmore than about of copper and antimony, which comprises forming anodesof such a material, and electrolyzing the anodes in a bath consisting ofa water solution of tree aromatic sulphonic acid and aromatic sulphonicacid salts of tin and lead, in which the tota1 acid in free, andcombined forms is from about 75 to about 600 grams per liter and whichcontains from about 3 to about 5 grams per liter of hydrochloric acid toprevent passivity of the anodes, whereby tin and lead are deposited atthe cathode.

2. The method of refining metallic materials consisting principally oftin and lead and containing copper and antimony which aggregate fromabout 8% to about 15% of the materials.

which comprises electrolyzing anodes of such a material in anelectrolyte consisting of a water solution of an aromatic sulphonic acidand aromatic sulphonic acid salts of tin and lead, in which the totalacid in free and combined forms is from about 150 to about 400 grams perliter and which contains from about 3 to about 5 grams which comprisesforming anodes of such a material, and electrolyzing the anodes in abath consisting of a water solution of free benzene disulphonic acid andbenzene di-sulphonic acid salts of tin and'lead, in which the total acidin free and combined forms is from about 75 to about 600 grams per literand which contains from about 3 to about 5 grams per liter ofhydrochloric acid to prevent polarization of the anodes, whereby tin andlead are deposited at the cathode.

4. The method of separating metals from metallic materials consistingprincipally of tin and leadand at least about 8% but not more than about15% of copper and antimony, which comprises iorming anodes of such amaterial, and eiectrolyzing the anodes in a bath consisting of a watersolution of free phenol sulphonic acid and phenol sulphonic acid alts oftin and lead, in which the total acid in free and combined forms is fromabout '75 to about 600 grams per liter and which contains from about 3to about 5 grams per liter of hydrochloric acid to prevent polarizationof the anodes, whereby tin and lead are deposited at the cathode.

5. The method of refining metallic materials consisting principally oftin and lead and containing copper and antimony .which aggregate fromabout 8% to about 15% of the materials, which comprises electrolyzinganodes of such a material in, an electrolyte consisting of a watersolution of free benzene di-sulphonic acid and benzene di-sulphonic acidsalts ot'tin and lead, in which the total acid in free and. combinedforms is from about to 400 grams per liter and which contains from about3 to about 5 grams per liter of hydrochloric acid to preventpolarization of the anodes, whereby tin and lead are deposited at thecathode.

6. The method of refining metallic materials consisting principally oftin and lead and containing copper and antimony which aggregate fromabout 8% to about 15% of the materials, which comprises electrolyzinganodes of such a material in an electrolyte consisting of a watersolution of free phenol sulphonic acid and phenol sulphonic acid saltsof tin and lead, in which the total acid in tree and combined forms isfrom about 150 to about 400 grams per liter and which contains fromabout 3 to about 5 grams per liter of hydrochloric acid to preventpolarization of the anodes, whereby tin and lead are deposited at thecathode.

- LOUIS S. DEITZ, JR.

Certificate of Correction Patent No. 2,393,239. January 22, 1946. LOUISS. DEITZ, JR.

It is hereby certified that error appears in the tinted epecification ofthe above numbered atent requiring eorreetion'ae follows: ago 2, secondcolumn, line 20, claim 4, ter the words lead and" insert containing' andthat the said Letters Patent should be read with this eorrection thereinthat t a same may coniorm to the record of the ease in the PatentOfliee.

Signed and sealed this 14th day of May, A. D; 1946.

[amt] IESLIE FRAZER, First Assistant Gmnmissiener of Patents.

